1. Field of the Invention
The present invention relates generally to a dewatering system and, in particular, relates to calibrating a sensor circuit in the dewatering system to compensate for accumulative contamination deposited on a sensor that is repeatedly immersed in water over its operating life.
2. Description of the Related Art
A dewatering system for an enclosed space, such as a sump pump for an electrical underground vault, often uses a sensor to detect for the presence of water in the enclosed space. The enclosed space is usually subject to waste water accumulation as water from rain, irrigation, leaks, and other sources enter and flood the enclosed space. The sensor is generally mounted at a fixed location in the enclosed space and generates a signal to indicate the presence of water when the sensor is immersed in water. One problem with using the sensor in a dirty environment is that there is an accumulative contamination deposited on the sensor each time the sensor is immersed in water. The sensor may become ineffective as its sensitivity is changed by the contamination. Regular maintenance, including periodic cleaning of the sensor, may be required to ensure reliable operations.